提出了改进的等残余高度算法用于加工自由曲面刀具路径生成。算法在生成相邻刀具路径轨迹时分两步,首先根据当前刀具路径轨迹,采用了Newton-Raphson迭代法精确求取刀具运动包络体上的点到自由曲面的距离,结合给出的Newton迭代法的迭代角度初值计算方法,精确求取满足要求的等残余高度点构成等残余高度线;然后根据求取的等残余高度线精确求取相邻刀具路径轨迹,求取过程类似。验证实例表明,该方法可极大地减少刀具路径轨迹长度,均匀曲面加工残余高度,提高曲面加工质量。
Improved ISO-scallop tool path generation algorithm is presented for free-form surface machining.The novel tool path generation algorithm includes two steps.Firstly,the Newton-Raphson iteration method is used to calculate the distance from the point of the tool swept volume to the free-form surface.The method for calculating the initial iteration angle combined with Newton iteration method is given to find the precise ISO-scallop point to construct the ISO-scallop curve according to current cutter contact tool path.Secondly,the neighbor cutter contact tool path is calculated from the ISO-scallop curve.The procedure is similar to the former one.Application example of the algorithm demonstrates that the total tool path length is reduced greatly,and the scallop distributed on the free-from surface is uniform and the machining quality is high.